Illumos 5118 - When verifying or creating a storage pool, error messages only show...

Illumos 5118 - When verifying or creating a storage pool, error messages only show one device

5118 When verifying or creating a storage pool, error messages
only show one device
Reviewed by: Adam Leventhal <adam.leventhal@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Boris Protopopov <boris.protopopov@me.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://github.com/illumos/illumos-gate/commit/75fbdf9
  https://www.illumos.org/issues/5118

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3567